Flue cleaning apparatus for water tube boilers



DeC- 29, 1931- c. AA. WESTERBERG `:a1-Al.v 1,838,600

' FLUE CLEANING' APPARATUS FOR WATER TUBE BOILERS Fild March 2l, 192s Patented Dec. 29, 1931 UNieg'rED STATES rP A'reN'll* OFFICE CARL AXEL ARVID WESTERBERG, OF DJURSHOLM, AND THURE GUSTAF HGLUND, OF

APPELVIKEN, SNEDEN, ASSIGNORS TO AKTIEBOLAGET SUPERIOR, OF STOCKHOLM;

SWEDEN, .A JOINT-STOCK COMPANY OF SWEDEN FLUE CLEANING APPARATUS EUR WATER TUBE vBIIIERS Application led 'March 21, 1928, Serial'NO. 263,289, and in '.Belgium April 1, 1927.

This invention relates to an improved soot blower construction for water tube boilers comprising a fluid injector nozzle rotatably arranged in a distribution box or casing and adapte-c. to discharge ya fluid jet in desired directions, said nozzle telescoping inthe casing, whereby the admission of fluid may be,

shut on' when the apparatus is not in operation.

According to the invention the apparatus is mounted in the wall of the setting of a water tube boiler plant between the grate and the lower row of tubes, so that the fluid jet may be directed towards the downward surfaces of the tubes, and the nozzle may be withdrawn into-the wall from the direct action of the flames, when not in use.

The accompanying drawings illustrate by way of example one embodiment of the invention. y

Fig. 1 shows on a reduced scale a vertical longitudinal section of the furnace of a water tube boiler plant provided with two soot Cleansers of the kind shown in Fig. 2. Fig. 2 is a longitudinal section of the sweeping apparatus, and Fig. 3 is an elevation of the outer part thereof. y

The mounting` of the apparatus in the boiler plant is shown in Fig. 1 where 8, 8 designate the lateral walls of the setting, 9 the grate and 10, 10 the water tubes of the plant. The twov soot Cleansers shown in this figure are situated between the grate 9 and the tubes 10, so that their conjugated jets sweep the whole lower surface of the tubes which are thus scoured outside.

In the form of embodiment shown in Figs. 2 and 3, 1 indicates the steam pipe, 2 the nozzle and 3 the opening thereof. The pipe l is surrounded by a distributing casing 15,

` to which steam is supplied through the inlet enening 16. Secured to the inner end of the' pipe 1 is a manoeuvring rod 22 projecting through a suitable packing 24 at the outer end of the casing 15 and having secured to it a hand wheel 25. The rod 22 is surrounded by a tube 17 inserted between the outer end of the casing 15 and a partition 26 in said casing which forms a guide forthe pipel l when sliding it axially and turning it by means of the rod 22 and the wheel 25. Prol vided in the said partition 26 are apertures 18 through which steam enters to the inner end'of the casing 15 and from there through the openings 12 into the pipe 1, when in the position shown in Fig. 2. v

In this position a projection 27 of the hand wheel 15 abuts` against the outerend surface of the casing 25 and prevents further inward movement of the rod 22 with the pipe 1 and nozzle 2. Y i

j In order to counteract the reaction force of thesteam jetr escaping through the nozzle 2 so that the movable parts l and 22 of the apparatus may, without difficulty, be held in their working position, Fig.,2, said parts are provided with a shoulder 2l formed by the annular end surface of the pipe l, the external diameter of which is somewhat greater than that of the manoeuvring rod 22, as `visible in Fig. 2, said shoulder being eX- posed to the steam pressure, as' will be described below, and being preferably so dimensioned that the steam pressure on it will slightly overcome the reaction force of the steam jet.

However, it is necessary that the steam is not permitted to escape through the nozzle 2 before it is moved into or substantially into its working position Fig. 3, since if steam could escape when the nozzle is vstill within the protecting casing 6 in Fig. 1, the said 'casing and also the surrounding masonry,

could bring about a breakage of the iappa-4 ratus.

To this end the steam pipe 1, to which steam is supplied through the openings n12, communicates through an axial bore 19 and a transverse channel 20 at the inner end of the rod 22 with the' annular space 28 besieV tween the tube 17 and the rod 22, the one bottom surface of which is just formed by the said shoulder 21. Consequently, when the steam pipe 1 is retracted within the casing 15 and the tube 1'4" to such an extent that the bores 12 are within the partitien 26, no steam can enter the pipe 1 and, thus, no steam pressure can act on the shoulder 21.

`lVlien, on the other hand, the movable pipe l is pushed inwardly (into the furnace) to such an extent that the first row of openings 12 moves beyond the partition 26, steam en ters the pipe 1 and escapes through the noz zle 2, and simultaneously steam passes through the bore 19 and the chanel 2O and exposes a pressure on the shoulder 21. Vhen both of the rows of openings 12 have moved beyond the partition 2G, the full steam presi sure exists within the pipe 1 and simultaneously also the reaction force of the escaping steam jet and the steam pressure on the shoulder 21 obtain their greatest value. Thus, as will be seen, the steam exerts a pressure on the shoulder 21 which alters gradually in correspondence with the alterations of the reaction force of the escaping steam jet.

In several boiler plants it is a disadvantage that the apparatus projects far from the settingwhen in its position of rest, i. e. when the pipe 1 with the nozzle 2 is moved into the protecting casing G, Fig. 1. In order to avoid this drawback, the manoeuvring rod 22 comprises two parts hinged together at 23, Fig. 2, and in the above-mentioned position of rest the said joint 23 is outside the packing 24; as visible from Fig. 3, and the outer part of the rod 22 with the hand wheel 25 hangs freely down. Since the steam is shut oli from the space 28 inside the tube 17, when the oint 23 passes through the packing 24, the joint may, it' desired, be made with a somewhat smaller diameter than the rod proper so that the edges of the oint do not damage the packing 24 when moved through it.

The device shown in the drawings and described hereinbefore only represents an embodiment of the invention which may be modified in its details without departing from the spirit and scope of the invention as deiined in the claim. Likewise the disposition of the apparatus in the plant may be varied, for instance by placing them coaxially with the tubes instead of transversely thereof.

lVhat we claim as new is A steam sweeping apparatus for boiler plants, comprising a steam distributing casing, a steam pipe movable axially in 'said casing, a nozzle at the free end of said pipe, means for moving said pipe and the nozzle axially, steam operated means for counter acting the reaction force of the steam jet escaping through said nozzle, and means for supplying steam to said steam operated means substantially in the same degree as the steam is supplied to said nozzle, said steam supplying means being so constructed and arranged as to be operable on axial movement of said steam pipe.

l'n testimony whereof we aiix our signatures.

CARL AXEL ARVlD WESTERBERG.

"ranas eUsTAF HGLUND.

llO 

